1. Field of the Invention
The present invention relates to an orthogonal transformer apparatus for use in high efficiency encoding of digital signals, e.g. a digital video signal or a digital audio signal.
2. Description of the Prior Art
It is known that two's complement signals are employed for data transmission between an orthogonal transformer and an encoder in a conventional orthogonal transformer device. The two's complement signals can easily be processed by arithmetic operations including addition, subtraction, multiplication, and division, whereby an arrangement of hardware for performing the operations will be simple. Although there are a variety of methods for expressing numbers, they will be more intricate in arithmetic operation than the two's complement signals and not commonly used in arithmetic operating apparatuses. However, two's complement input signals which have high correlation, e.g. video signals, tend to appear in proximity to zero when having been processed by orthogonal transformation. In particular, whenever a two's complement signal is changed from positive to negative or vice versa, almost all 1 and 0 bits of the signal will be inverted. As the result, the inversion of 1 and 0 bits causes unwanted changes in the current and voltage during transmission of such signals carrying values proximal to zero, thus causing noise signals in the apparatus.